Electromagnetic apparatus for the transmission of images



July 2 2, 1930. L. THURM" I 1,771,366

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* fi/w 52% July 22, 1930. THUR 1,771,360

7 SLBCTROIAGIIBT IC APPARATUS FOR THE TRANSIISSION OF IIAGES mm: Jan. 2a. 1928 2 Sheets-Sheet 2 Myra ram Patented July 22, 19550 UNITED STATES LEON THURM, or suansnas, r'aanon ELECTROMAGNETIC APPARATUS FOR THE TRANSMISSION 01 IMAGES Application flledjanuary 23, 1928, Serial No. 248,924, and in Irance February 5, 1927.

The present invention relates to an electromagnetic apparatus for the transmission of images at a distance. Hitherto the radio trar'ls'sr'nission ofstationary or moving images required the use of apparatus of, a complicated nature which cannot be employed by radio amateurs. a

Myinvention obviates such drawbacks by the use of an apparatus whereby images may be sent by a transmitting station and received by a receiving station of any known type.

' The said apparatus consists essentially oi a plurality of steel bands preferably wound in a spiral. "Each spiral band travels between the poles of an electromagnet carrying a current which is modulated by a photo-electric cell and is suitably amplified; said bands serve for the magnetic recording of the more or less illuminated points composing the moving picture to be transmitted. Since each photoelectric cell explores only a part of the image, the number of such bands is made equal to the number of cells, which number will vary with the sensitivenessof the cells. I

" 'VVhen the magnetic record has been made upon the'steel'bands. these are caused to travel in succession between the poles of an electromagnet occupying the place of the microphone of a radio transmitting station of the usual type. At the receiving station similar steel bands are caused to travel at the same time between the poles of an electromagnet which is connected in the place of the telephone or loud speaker. The image is reproduced by circulating simultaneously the steel bands of the receiving station between the poles of electromagnets destined to modulate the currents of the optical system by which the image is thrown on the screen.

The appended drawing shows by way'of example an embodiment of the invention.

Fig. 1 shows the method of making the record upon the steel bands at-the transmitting station, and also the connections between the electro-magnets and the optical device at the receiving station.

Fig. 2 shows a steel band wound in a spiral to reduce the size and held therein by a suitable substance so as to form a disk.

Fig. 3 is a sectional view of Fig. 2,

Fig. 4 shows the section of a disk in which the steel band extends on both sides so as to form a double-faced disk, so that only half the number of disks need be used.

Fig. 5 is a view on a largerscale showing a part of disk in which the band on each side travels between the poles of an electromagnet.

Fig. 6 shows a known transmitting station in which the microphone is replaced by an electromagnet.

Fig. 7 is an analogous View of a receiving station in which the telephone is replaced by an electromagnet.

Referring to the drawing, 1 represents the photo-electric cells or bulbs, these being connected to amplifiers 2 which have the electromagnets 3 connected to their output ends. Between the poles of the said magnets are caused to travel the steel bands 4 disposed in spiral form in the disks 4 of a suitable substance. The several disks are mounted on a common shaft 5 by which they are rotated at the same time.

In Figs. 6 and 7 6 is the transmitting sta- 'motion of this image and I may thus move, in

succession and in the proper time, the points correspondingto the n parts of the image over the n photo-electric cells.

, Each of the a electric circuits comprising the n photo-electric cells or bulbsproceeds into a suitable amplifying system. Thecurrents, properly amplified, proceed when issuing from the amplifiers into n electromagnets which form magnetic records u on n steel bands which travel continuously et-ween the poles of the said magnets. I a

The n steel bands are then caused to travel successively in a given order and at the proper. speed between the poles of an electromagnet V which is substituted for the microphone in a transmitting station, known per se. The steel bands thus modulate waves produced-by the said transmitting station in the same manner as a microphone transmitter.

The waves sent out by the said station are received by a receiving station which may be of any usual type, and in which thetelephone receiver or the loud speaker is replaced by an electromagnet. This latter forms a record upon a set of n steel bands traveling through its poles in concordance with'the like set of bands at the transmitting end, and at about the same speed. After the steel bands at the receiving end have thus received the record, they are disposed, in the order corresponding to the order employed at the transmitting end, between the poles of n electromagnets, and are made to travel at the same time and at the proper s eed between the poles of said magnets. Eac of the said electromagnets is connected to a suitable amplifying system and variesthe electric currents flowing therein, due to the record on the steel band. Such currents, when thus properly amplified, will vary the luminous intensity of a suitable optical combination, comprising for instance neon lamps. I may employ as many neon lamps as there are photo-electric cells in the photoelectric retina acted upon by the moving image to be transmitted. V The said neon lamps by a movement analogous to tie movement by which the photo-electric cells are enabled to explore the image, will thus act upon a screen on which the transmitted image is reproduced. I

In addition to the advantages above mentioned, the said arrangement considerably simplifies the synchronizin even a watch or clock may purpose.

By means of the steel bands whose magnetic record will remain as long as this record is not effaced by means of a permanent magnet or the like, the transmitted image may be reproduced as often as desired. After the record has been efi'aced by suitable means, the bands are ready for a new record.

In order to reduce the size of the apparatus, the steel bands are wound in a spiral coil and are held in this shape b a suitable substance; the bands may extend 'rom this substance on e used for this either side, so'that the record can be made on" system, sin ce a multiplex device at the transmitting and the receiving ends, by the multiple modulation of one or more sets of waves, or simply by waves of different lengths.

The said wires, bands or disks can thus be employed for the reproduction of ima es as well as sounds, as may be desired, and thus provide a repeating apparatus for images or sounds on the radio principle.

Obviously, the details of construction and assembling may be varied as desired.

The several constructional parts of the said apparatus can be replaced by other parts having like functions and producing the same re sults. For instance, instead of a disk I may employ a steel cylinder or endless steel ribbon.

It is further evident that I may employ any suitable substances, metals or products adapted for the manufacture of the said apparatus.

I claim.

1. An apparatus for the transmission of images comprisin a photo-electric retina consisting of a p urality of photo-electric cells disposed in electric circuits, said cells being adapted to explore simultaneously the luminous points of an image, a plurality ofv lot In testimony whereof he has afiixed his signature.

LEON THURM.

each side as in the case of a phonograph disk.

In this manner only half the number of disks need be used.

By the additional use in the transmitting and the receiving station of a disk, wire or band of a special nature for records and reproduction of the voice, I am enabled to transmit not only the image, but also the voice and music which will be reproduced in synchronism with the images at the receiving station.

The time required for the successive transmission of the different wires, bands, disks or cylinderscan be much reduced by the use of 

